Flutter环境下无法部署Firebase Cloud Function问题求助

全新安装Flutter环境，使用TypeScript完成Firebase初始化后，部署示例云函数时出现大量TypeScript编译错误，已升级Mac上的Flutter和Firebase CLI。

错误信息 #

node_modules/@types/express-serve-static-core/index.d.ts:99:68 - error TS1110: Type expected.

99 type RemoveTail<S extends string, Tail extends string> = S extends `${infer P}${Tail}` ? P : S;
                                                                      ~~~

node_modules/@types/express-serve-static-core/index.d.ts:99:77 - error TS1005: '}' expected.

99 type RemoveTail<S extends string, Tail extends string> = S extends `${infer P}${Tail}` ? P : S;
                                                                               ~

node_modules/@types/express-serve-static-core/index.d.ts:99:78 - error TS1128: Declaration or statement expected.

99 type RemoveTail<S extends string, Tail extends string> = S extends `${infer P}${Tail}` ? P : S;
                                                                                ~

node_modules/@types/express-serve-static-core/index.d.ts:99:80 - error TS1005: ';' expected.

99 type RemoveTail<S extends string, Tail extends string> = S extends `${infer P}${Tail}` ? P : S;
                                                                                  ~

node_modules/@types/express-serve-static-core/index.d.ts:101:33 - error TS1005: ';' expected.
                                                   ~
Found 127 errors.

npm ERR! code ELIFECYCLE
npm ERR! errno 2
npm ERR! functions@ build: `tsc`
npm ERR! Exit status 2
npm ERR! 
npm ERR! Failed at the functions@ build script.

我的index.ts代码 #

import * as functions from "firebase-functions";

// Start writing Firebase Functions
// https://firebase.google.com/docs/functions/typescript

export const helloWorld = functions.https.onRequest((request, response) => {
  functions.logger.info("Hello logs!", {structuredData: true});
  response.send("Hello from Firebase!");
});

解决方案 #

这些错误源于当前使用的TypeScript版本不兼容${infer P}${Tail}这类模板字符串类型语法（该特性从TypeScript 4.1版本开始支持），按以下步骤修复：

• 进入functions目录，打开package.json，将devDependencies中的typescript版本升级到4.1.0或更高，示例：

  "devDependencies": {
    "typescript": "^4.9.5"
  }
  

• 删除functions目录下的node_modules文件夹和package-lock.json文件
• 在functions目录执行npm install重新安装依赖
• 检查tsconfig.json的compilerOptions配置：
  • 将target设为ES2018或更高版本
  • 确保lib数组包含ES2020或更高版本，示例：

    "compilerOptions": {
      "target": "ES2018",
      "lib": ["ES2020"],
      "module": "commonjs",
      "outDir": "lib",
      "rootDir": "src",
      "strict": true,
      "esModuleInterop": true,
      "skipLibCheck": true,
      "forceConsistentCasingInFileNames": true
    }
    

• 执行npm run build验证编译是否通过，之后再部署云函数

内容的提问来源于stack exchange，提问作者Jason Simard